Improvement in the giffard injector



UNITED STATEs PATENT OFFICE.

WILLIAM SELLERS, OF PHILADELPHIA, PENNSYLVANI A.

IMPROVEMENT iN THE GIFFARD INJECTOR.

Specificationforming part of Letters Patent No. 49,445. dated Augllh 15, 1865.

.To all whom it may concern:

Beit known that I, WILLIAM SELLERS, of Philadelphia, in the State of Pennsylvania, have invented a new and useful Improvement iu the Giiiard Injector, whereby this instrument is made self-regulating; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

` In this instrument, as heretofore constructed, 'i

the supply of water and steam has been regulated by means of screws, levers, or other de-` vices controlled by hand, so that wherever the tension or pressure of the steam varies, the attendant is obliged to readjust the supply of water in order that the instrument may work to the best advantage, and whenever the pressure falls below the point to which the instru ment has been adjusted a readjustment bccomes necessary to prevent a'waste of water at the overflow...

In many boilers, such as the locomotive, and others having asmall water and steam capacity compared to their heating-surface, and where the demand for steam is very irregular, the variations of the steampressure are considerabie and very frequent, and the amount of at= tention required for regulating the injector becomes a serious inconvenience. j

The object of my invention is to make this regulation self-actin g and dependent upon the amount of steam or water admitted to the instrument, and to utilize a power until now wasted at the overflow. The overflow, as heretofore used, has been for the purpose of permitting the escape of the water before it has attained sufficient velocity to enable it to enter the boiler when the jet is rst started ,and also to permit, when the jet is in motion, the superabundant water or steam to escape without `being made for waste, an amount of lateral pressure may be obtained at the point of overiiow nearly equal to that inthe boiler. It has also beenlong known that the liuid-jet,in passing the point of ovcriiow, will'uot, when in excess, carry along with it into the boiler any iiuid that may bein contact with it, so that, it the overliow-chamber should be closed up, a moderate vacuum canbe produced there by this ac` tion of the jet.

The nature of myinvention consists in usin g the pressure created by an overiiowingjet to adjust the parts of the instrument so as to check the tendency to overflow, and in using the partial vacuum created by an excess of steam over water-supply to adjust the instrument to the new conditions without wasting any 'water at the point of overflow.

Themeans employed by me for utilizing the power mentioned will be'more fully uuderi stood from the following description,in which I illustrate la manner of regulating the iustrument by an automatic adjustment of the Watersupply only.

The outer shell or case ot' the injector Imake in two parts, A and B, ,united by a nut, C, having a right-hand screw-thread in one side and a left-hand one in the other, with corresponding threads on the parts A and B. The part A is provided with two nozzles, `l), for the admission of y steam, and E for the admission 'of the water, the two being sepaV rated by the plate F. In the center of the plate F, I provide a nozzle, G, for the steamjet, the amount of steam that can be discharged from this nozzle being regulated bythe tapered plug H, which may be operated by a screw, lever, or other convenient device.

The interior ofthe caseA beyond the waternozzle E is bored out for a short distance, and fitted with a cylindrical brass lining, a a, which is turned out to receive the packing b bin the piston I. This piston forms the upper or receiving end of the receiving and discharging pipe J J, which has its axis coinciding with that of the steam-discharge nozzle Gr. The

pipe J J is so arranged as to be capable of moving to or from the nozzle G, so as to enlarge or contract the annular space between the exterior of G and the interior of the receiving-pipe, thereby governing 'the amount of water which can be admitted to the action of the steam escaping from the nozzle G. The pipe J J is j gradually contracted through about half its length, when it commences to enlarge, and gradually increases until it discharges into the perforated chamber K, and subsequently into the space between it; and

the ease I3, which surrounds it. The part Il of the outer shell or case is provided with a nozzle, L, from which the water discharged from the chamber K can be conducted into the boiler. There must be provided a waste cock or valve to enable the water escaping from the p erforatcd chamber K to be discharged freely into the atmosphere, for the purpose of establishing thejet when first started. Se soon as this is accomplished this waste must be closed, and will be of no further use so long as the jet is in motion. It may be placed in any convenicntposition, and is shown upon the pipe leading to the boiler. Between this and the boiler a check-valve mustl beemployed to prevent the return of the water when the in-v strument is stopped.

The shell or case I3 is closed at one end by a plate or head, M, which projects into the ease A, in which it is accurately fitted, for the purpose of maintaining the axis of the receiving and discharging pipesJ J in the line of the axis of the steam-nozzle G. The other end of the case I3 is closed by a screw-cap, N, accurately fitted, so as to prevent any leakage of air or water. Between the cap N and the head M, I provide a second head, O, forming a chamber, I), between them, the use of which will be hereinafter described, both heads M and O bein g provided wi th stuffin gboxes,which allow the pipe J J and the extension J of the chamber K to play freely longitudinally without permitting` the escape of any water discharged from the chamber K.

.Between the heads M and O, and opposite the nozzle L, I form aprojection, It,cast with the outer case, l5, through which I drill a small hole, c e, making a communication between the upper chamber in the case A and the chamber I in ease B; and it is imlportant that this shall be perfectly sound, so r s to prevent any escape of water into it that has once passed from the perforated chamber K. Through the axis of the receiving` and discharging pipe J J, and a short distance above its smallest diameter-that is, toward its receiving end- I drill a small. hole, d d, which I call the overilow,7 for the purpose of allowing an escape of water when a too abundant supply is admitted at the receiving end.

The operation ofthe instrument is a-s follows, viz: The waste-cock between the instrument and boiler must rst be opened; then admit the supply of water, allowing it to flow through this waste 5 let on the steam, when an immediate increase will take place in the volume of water escaping at the waste, showing that the jet has been established. The waste-cock may new be closed, and the water will tiow into the boiler. But in case there should be too much water admitted vat the receiving end of the pipe J J, the superabundance will escape through the holes d d into the chamber in the ease A, thence through the hole c c into the chamber I) in the ease I3, and will continue so to do until both chambers are full, when it will exert a pressure upon the end J of the pipe .I J and piston I, causing the whole to nieve toward the steam-discharge nozzle G, thus diminishing the water-supply until the quantity admitted is in exact proportion to the supply of steam. The relative positions of these nozzlcs will then remain the same until some change takes place in the pressureof the water-supply or the tension of the steam.

Supposing, now, the tension of the steam in the boiler should increase, or that the tapered plug II should be drawn back fr om the opening in the nozzle G, so that a large' quantity of steam should be discharged, the increased velocity of the jet will carry along'with it into the boiler some of the water which had previously escaped through the openings d d, causing a partial vacuum under the piston I. The pressure of water will then cause it to recede from the nozzle Gr, thus admitting more water, until the equilibrium is again established.

The lower chamber, IJ,-.is not necessary to the' operation of the instrument; but by its use I increase the amont of surface exposed to pressure from the overflow, thereby increasing the sensitiveness of the adjustment, and also prevent the escape of any waste in case the packing in the head O should leak.

From the foregoing it is evident that the instrument, when constructed as described,.has its water-supply automatically adjusted to suit any condition of` steam-supply, whether dependent upon variation of boiler-pressure or the regulation of the steam-supply by hand, the quantity of water delivered by the instrument depending wholly upon the amount of steam admitted. Hence in working the instrument it isV only necessary to regulate it for capacity by adjusting the steam-supply.

To nake the instrument entirely self-adjusting axld capable of maintaining the water in the boiler at a uniform height, requires only that the position of the plug which regulates the steam escaping from the steam-discharge nozzle should be regulated by the height of the water in the boiler. Almost any of the immerous devices in use which govern the watersupply by the height of the water in the boiler would answer the purpose, and could be readily applied; and to determinewhether the jet is in motion, a light safety-valve may be attached to either the upper or lower overflow-chamber, and weighted to an extent sufficient to produce a pressure in this chamber capable of moving the receiving and discharging pipe. Then, with a check-valve in the water-supply pipe which will permit the water to flow to the instrument, the failure to work would instantly be notied by the escape of steam and water at this safety-valve.

'The water-supply may be regulated by va- V rious other methods than by the adjustment of the receiving-pipe; and this pipe may be adj usted by the weight of the water escapi-n g at the overflow without regard to its pressure, the theory of my invention consisting in using the overilow-water either inits escape greater -or less quantity or in its tendency to escape, to

perform one functional adjustment, while the drawing back ofthe overflow-water or the tendency to draw back performs the opposite functional adjustment. I have described this adjustment as being made in the water-supply only; but it must be evident to any intelligent 'mechanic that the power which I have discovered in the instrument may be made to control the regulation of other parts of the instrument, either in connection with the water-supply or entirely distinct therefrom. Thus, if the lower cap, N, be removed, the hole c c stopped up, and a yoke be made to unite the lower part of the discharge-pipe J J to the nut of the tapered plug H, and this nut 'of H be made free to slide endwise in the outer casing, A; or if it be made a part of'this yoke, the yoke being on the outside of the case A, the water and steam supply would be adjusted simultaneously, for when the steam was in excess the tendency to draw back the overflow-water, or the drawing it back, would pull down the receiving-pipe J J to give more water, and also the tapered plug H, cutting off some of the steam. Thus the adjustment would be effected with less movement of the discharging-pipe J J. Or if the overflow-water shouldbe allowed to pass into a supplementary cylinder and there act against a movable piston, that piston could be attached to any part of the instrument requiring adjustment. Thus it`could as well move a valve in the steamsupply pipe, or even the tapered plug H to regulate the steam-supply, as it does the discharging-pipe J J. Hence I do not limit my invention to the special devices shown, nor tol the particular arrangements described; but What I claim as new, and desire to secure by Letters Patent, is-V The use of the overflow d d or its equivalent in the Giiard injector, in combination with a reservoir to retain the overflow-water in contact with the jet, for the purpose specified.

WM. SELLERS.

Witnesses: i

Guns. W. PEALE, J As. H. BAILEY. 

